
where \(\pi ^r\)  and \(\pi ^s\)  are the marginal probability vectors at \(r\)  and \(s\)  respectively, so that the sign of \(\det P^{rs}\)  becomes irrelevant. The result in [1]} shows that if the values of an additive function are known between the pairs of all terminal nodes, then under the conditions of Proposition REF , the topology and the value of the function on all edges of the topology are determined. As \(f\)  can be calculated from pairwise distributions between terminal nodes, so the topology and the value of \(f\)  on every edge can be determined.
